1. Field of the Invention
This invention relates to digital rights management for scanned copies of documents, and in particular, it relates to a method implemented on a scanner for applying digital rights to scanned documents.
2. Description of Related Art
Documents traditionally available only in hard copies are increasingly also available in digital copies. In fact many documents nowadays are prepared, generated, stored, distributed, accessed, read or otherwise used electronically in digital file formats such as the Portable Document Format (PDF). With the wide use of digital documents and digital document processing, digital rights management systems (“DRM” or “RMS”) are increasingly implemented to control user access and prevent unauthorized use of digital documents. The rights involved in using a digital document may include the right to view (or “read”) the digital document, the right to edit (or “write”) the digital document, the right to print the digital document in hard copies, the right to copy the digital document, etc. A user may access a digital document by acquiring (or being assigned) one or more of these rights.
DRM systems are generally implemented for managing users' rights to the digital documents stored in the systems. In a current DRM system, each digital document is associated with a rights management policy (or simply referred to as policy in this disclosure) that specifies which user has what rights to the document, as well as other parameters relating to access rights. Many such policies are stored in a DRM server (also called RMS server). The server stores a database table that associates each document (e.g. by a unique ID, referred to as document ID or license ID) with a policy (e.g. by policy ID). Each digital document may also have metadata that contains the document ID. When a user attempts to access a document (either a document residing on a server or a document that has been downloaded or copied to the user's computer) using an application program such as Adobe™ Reader, the application program contacts the DRM server to request permission. The DRM server determines whether the requesting user has the right to access the document in the attempted manner (view, edit, print, etc.), by determining the policy associated with the document and then referring to the content of that policy. The DRM server then transmits an appropriate reply to the application program to grant or deny the access. If access is granted, the server's reply may contain a decryption key to decrypt the document.
Scanner devices (including multi-function printers (MFP) that have printing, scanning and copying functions integrated in one device, or a device that has only a scanning function) are used to scan hardcopy documents to generate digital documents. Some scanners are equipped with DRM management functions to manage digital rights of the digital documents created by the scanner. For example, in one known DRM system, a scanner is connected to the DRM server by a network. When an operator uses the scanner to scan a hardcopy document into a digital document, the scanner prompts the operator to specify a rights management policy to be associated with the digital document. The scanner transmits a copy of the scanned digital document to the DRM server along with the operator's selection of right management policy. The DRM server applies the policy to the digital document, e.g., by adding the document ID of the digital document to the database table and associates it with the policy ID of the selected policy, and also embedding the document ID in the metadata of the digital document. The DRM server sends the protected version of the digital document back to the scanner. The operator at the scanner can then distribute the protected document, for example, by storing it or emailing it to various users. Here, a protected document refers to a digital document that has a rights management policy applied to it by the DRM server. Later, when a user attempts to access the protected document, access control can be accomplished by the DRM system in the method described above. An example of a scanner having DRM functions is the Canon imageRUNNER ADVANCE device, described in a document entitled “Safeguarding information Within Documents and Devices,” available on the internet at http://www.usa.canon.com/CUSA/assets/app/pdf/ISG_Security/brochure_run_iradv_security_pdf.